mssurrey

I have a 2013 S5 (B8.5). Bought new and placed a K&N filter in it at the time. I've recently replaced the K&N (couldn't be bothered cleaning it) but the issues pre-date that. 50K miles (so low mileage vehicle). Never any issues until for the past 6 months or so when both the EPC light and the CEL have started to come on. Seems too early to have to deal with this crap.
The EPC seems to be random - when I switch the engine off, it clears but when I accelerate hard, it comes on again (until I switch the car off again). I read somewhere that this is, or could be, an oil pressure switch issue?
The CEL (according to my OBD-II scan tool - Rosstech on the way) shows an active MAP/MAF throttle position (correlation) issue. Code P0068.

My questions are:
Are these two issues related?
Is there anything I should check before I clean the Throttle Body?
Is there anything I should be aware of when doing so? Damage, care etc?
Do I need to clean all 3 MAP sensors? Should I clean these or just change them for new?
If the EPC is an oil pressure switch issue, can I change these myself? Where are they located?

Sorry for the questions and thanks guys